Targeting of Two Signal Transduction Pathways to Different Regions of the Bacterial Cell

Mol Microbiol. 2003 Nov;50(3):763-70. doi: 10.1046/j.1365-2958.2003.03716.x.

Abstract

Components of bacterial chemosensory pathways which sense via transmembrane receptors have been shown to localize to the cell poles. Many species, however, have operons encoding multiple putative chemosensory pathways, some including putative cytoplasmic receptors. In-genome fusions to single or multiple genes encoding components of two chemosensory pathways in Rhodobacter sphaeroides, cheOp2 and cheOp3, revealed that while sensory transducing proteins associated with transmembrane receptors and encoded on cheOp2 were targeted to the cell poles, the proteins associated with putative cytoplasmic receptors and encoded on cheOp3 were all targeted to a cytoplasmic cluster. No proteins were localized to both sites. These data show that bacteria target components of related pathways to different sites in the cell, presumably preventing direct cross-talk between the different pathways, but allowing a balanced response between extracellular and cytoplasmic signals. It also indicates that there is intracellular organization in bacterial cells, with specific proteins targeted and localized to cytoplasmic regions.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Bacterial Proteins / genetics
  • Bacterial Proteins / metabolism*
  • Cell Membrane / metabolism
  • Chemotaxis / physiology
  • Cytoplasm / genetics
  • Cytoplasm / metabolism*
  • Luminescent Proteins / genetics
  • Luminescent Proteins / metabolism
  • Membrane Proteins / genetics
  • Membrane Proteins / metabolism
  • Methyl-Accepting Chemotaxis Proteins
  • Methyltransferases / genetics
  • Methyltransferases / metabolism
  • Microscopy, Electron / methods
  • Operon
  • Recombinant Fusion Proteins / genetics
  • Recombinant Fusion Proteins / metabolism
  • Rhodobacter sphaeroides / genetics
  • Rhodobacter sphaeroides / metabolism*
  • Signal Transduction*

Substances

  • Bacterial Proteins
  • Luminescent Proteins
  • Membrane Proteins
  • Methyl-Accepting Chemotaxis Proteins
  • Recombinant Fusion Proteins
  • yellow fluorescent protein, Bacteria
  • CheW protein, Bacteria
  • CheB protein, Bacteria
  • Methyltransferases
  • chemotaxis methyltransferase